Thermoplastic polymers of vinyl chloride are used for a variety of purposes such as pipes, tubing, hose, sheet, shoe soles, coated fabrics, wire covering, flooring, and weatherstripping. Because such thermoplastic polymers are generally brittle and exhibit poor elongation and abrasion properties, it has been common practice to add various modifiers such as thermoplastic polyurethanes, monomeric plasticizers, low molecular weight aliphatic polyesters, and nitrile rubber; however, blends containing such modifiers suffer a variety of disadvantages such as volatility, hydrolytic instability, poor abrasion resistance, susceptibility to fungus, processing difficulties, and poor low temperature properties. There has been a need for a modifier for thermoplastic polymers of vinyl chloride which imparts good abrasion resistance, impact resistance, fungus resistance, improved processability, good low temperature properties and improved hydrolytic stability to such modified compositions.